Forgefix corrugated roofing screw round head pozi zp forgefix 10crsc these forgefix pozidriv round head corrugated roofing screws are zinc plated for increased corrosion resistance they come complete with a specially designed plastic fold over cap to suit installation of corrugated roofing the plastic cap has a large surface area to improve weather resistance screw size 4 0 x 50mm pozi suitable for fixing corrugated sheeting to timber sub frames zinc coatings prevent oxidation of the